“Reason is, and ought only to be the slave of the passions.”
“Reason is the slave of passion.”
“You will find that reason, which always ought to direct mankind, seldom does; but that passions and weaknesses commonly usurp its seat, and rule in its stead.”
“The undisciplined are slaves to moods, appetites and passions”
“He only employs his passion who can make no use of his reason.”
“I am a complete slave to vocabulary, I ought to have named my cat Roget.”